The present invention relate to a stress measuring method and system, more specifically, a stress measuring method and system for measuring a lattice strain amount and a stress value in an infinitesimal region by convergent-beam electron diffraction method.
It is known that when a stress is applied to a crystalline material from the outside, lattice strains takes place and influence various properties of the crystalline material. Especially, lattice strains accompanying high integration and downsizing of semiconductor devices is an important factor for deciding the device characteristics of the electronic devices. On the other hand, lattice strains generated in crystalline materials are positively utilized to thereby improve or suppress the degradation of the electronic characteristics of electronic devices. Accordingly, to design required devices, it is important to measure stresses, which are a cause for the lattice strains of the crystalline materials forming electronic devices.
A lattice strain, which can be grasped as a change rate of a lattice constant, has been measured by lattice constant measuring methods, such as x-ray diffraction method, Raman analysis, convergent-beam electron diffraction method, etc. Among them, the convergent-beam electron diffraction method, which can decide the lattice constant with space resolving power of the nanometer-order, is used in measuring the lattice strain of small electronic devices.
The convergent-beam electron diffraction method is described in, e.g., Reference 1 (Japanese published unexamined patent application No. Hei 06-036729), Reference 2 (Japanese published unexamined patent application No. Hei 07-169811), Reference 3 (Japanese published unexamined patent application No. 2000-009664) and Reference 4 (Japanese published unexamined patent application No. 2004-077247).